1. Field of the Invention
The present invention relates to an electronic camera that obtains electronic image data by capturing a subject image with an image-capturing device constituted with a CCD image sensor or the like.
2. Description of the Related Art
There are electronic cameras known in the related art that determine the exposure quantity to be achieved during a photographing operation based upon the difference between the largest value and the smallest value indicated by image-capturing signals output from an image-capturing device and executes the photographing operation at the exposure quantity thus determined (see, for instance, Japanese Laid Open Patent Publication No. H 10-322592). In the electronic camera disclosed in Japanese Laid Open Patent Publication No. H 10-322592, a histogram is prepared by using image-capturing signals each corresponding to a pixel which are obtained during a photographing operation and a gradation characteristics curve to be used for gradation correction (γ control) is determined based upon the histogram. By determining the gradation characteristics in this manner, the saturation of image-capturing signals in a high brightness range is suppressed and thus, the occurrence of so-called white flare is minimized.
The electronic camera disclosed in Japanese Laid Open Patent Publication No. H 10-322592 requires a considerable length of time for the histogram preparation processing and also it is not suitable for photographing scenes containing numerous point light sources such as night time city scenes. Namely, since the image-capturing signals each corresponding to a pixel, which indicate the point light sources, are targeted for the saturation suppression, the brightness levels of the point light sources are lowered and the photographed image fails to show the full beauty of the nocturnal scene as a result.